If green technology is often perceived as a modern innovation, its Welsh roots stretch a century back.

“Some of the smallest villages in Wales were using renewable energy technology to generate their own private electricity supply more than 100 years ago, long before most of the big cities,” says Keith Jones, an expert from National Trust Wales, which is working with the Heritage Lottery Fund in a new project aiming to reveal more about bygone power supply ingenuity.

“In fact, rural Wales has been generating hydro-electricity for almost 150 years – it was at the cutting edge of hydro-electricity development, with a small army of foundries, engineers and dedicated families driving development and innovation.”

As part of a programme, All our Stories, organisers are encouraging the public to come forward and help inform their research.

The campaign will support the BBC Two series The Great British Story, and the accompanying blog, called National Trust Going Green, is full of quirky stories and initiatives.

“We are a nation of storytellers,” says Jennifer Steward, of the Fund.

“We want to explore and dig deeper into our past and discover more about what really matters to us.

“This is exactly what the grant will do for the National Trust Hidden Hydro Project. They are embarking on a real journey of discovery.”

Jones says all the buildings involved will be documented and photographed for an exhibition planned in 2013.

“Many of the hundreds of old hydros were simply locked up, left or lost when the National Grid appeared,” he explains.

“We’re appealing to anybody with information about the whereabouts of these engineering wonders to get in touch.

“They may have one at the bottom of the garden, farm or down the street.

“Some of these sites may be able to come back to life once more to generate again, as renewable energy is the key to both our past and our future.”